process – What Does This Process STAT Indicate?

processprocess-managementpsstat

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If you check the STAT column in above image you will see Ss S S< SN and R+
What does this indicates ? Process states.
If yes,Then what is the significance of 'Ss S< SN and R+'?

Best Answer

These are indeed the process states. Processes states that ps indicates are:

D Uninterruptible sleep (usually IO)
R Running or runnable (on run queue)
S Interruptible sleep (waiting for an event to complete)
T Stopped, either by a job control signal or because it is being traced.
W paging (not valid since the 2.6.xx kernel)
X dead (should never be seen)
Z Defunct ("zombie") process, terminated but not reaped by its parent.

and the additional characters are:

< high-priority (not nice to other users)
N low-priority (nice to other users)
L has pages locked into memory (for real-time and custom IO)
s is a session leader
l is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
+ is in the foreground process group 

You could also find this all by looking in the man page for ps, specifically the PROCESS STATE CODES section.